Inserter for the positioning of an intrauterine device

ABSTRACT

An inserter for the positioning of an intrauterine device in the uterus, which inserter includes a plunger, a handle attached to the plunger, a string for the removal of the IUD, a locking device to lock the string in such a way that the IUD remains immobile in relation to the plunger, and a protective tube around the plunger. The protective tube is arranged in relation to the plunger in such a way that it can be pushed, at the forward end that goes into the uterus, past the plunger at distance (L) , which corresponds substantially to the length of the IUD assembled for insertion. The stop members ensure that the front edge of the protective tube is stopped in a configuration in which the hemispherical tips of the wings of the transverse member of a T-shaped IUD remain partly uncovered by the protective tube, but the wings nevertheless remain pressed against each other.

BACKGROUND OF THE INVENTION

The invention relates to an inserter for the positioning of anintrauterine device. The invention also relates to an assembly of theinserter and the intrauterine device.

An intrauterine contraceptive device (also called an intrauterine deviceor IUD) in common use is a T-shaped object fabricated of plasticmaterial, which object consists of an elongate member having at one enda transverse member comprising two wings, the elongate member and thetransverse member forming a substantially T-shaped piece when the deviceis positioned in the uterus. The elongate member has a copper wire woundpartly around it, said wire being capable of releasing copper ions. Thedevice has an attached thread long enough to protrude out of thecervical canal when the device is in position in the uterus. The deviceis introduced into the uterus by means of a separate inserter, thedevice being in a contracted state during insertion in order tofacilitate the introduction of the device through the cervical canal.The tips of the wings of the transverse member are hemispherical inorder to facilitate the introduction of the device, contained within theinserter, through the cervical canal.

In addition to T-shaped IUD's also devices shaped like a ring, a "7" oran "S", for example, are known.

Also IUD's capable of releasing hormones or other active agents exist,and they are used either for contraception or for the treatment ofhormonal troubles.

Several types of inserters exist for the positioning of intrauterinedevices. The most common inserter for T-shaped IUD's consists of aplunger with a handle, inside a protective tube. Preparative to thepositioning the device in the uterus, the IUD, which is located at theend of the plunger, is retracted towards the handle so that the deviceenters the tube, and the wings of the transverse member of the devicebend towards each other. Then the protecting tube with its contained IUDare introduced through the cervical canal. When the device is correctlypositioned it is released by retracting the protecting tube towards theoutside. The wings of the transverse member then expand, and the deviceassumes the shape of a "T".

A contraceptive device, which is available on the market and whichreleases levonorgestrel, consists of a T-shaped IUD having an elongatemember fabricated of polyethylene equipped with a reservoir adjustedaround it and containing the hormone levonorgestrel. The device is soldin sterile packaging together with the inserter with the plunger, whichis a solid piece, contained within the protecting tube. The T-shapeddevice is positioned at the forward end of the plunger with thehormone-containing elongate member protected by the tube. The wings ofthe transverse member, on the other hand, are expanded in order toprevent fatigue. The strings by which the T-shaped device is retractedtowards the outside run between the plunger and the protective tube andend at the end of the handle. FIG. 1 illustrates one such device. TheT-shaped IUD's having an elongate member wound with copper wire arepackaged in a similar manner.

A problem associated with the inserters of T-shaped devices containingactive compounds regards the attainment of the correct positioning ofthe IUD within the protective tube. The difficulty is due to the greaterdiameter of the elongate member of these devices as compared to thecopper wire-containing IUD, which means that the diameter of theprotective tube also is greater. The hemispherical end pieces of thewings of the transverse member are small in relation to the diameter ofthe protective tube. It is therefore extremely important that these endpieces are in the exactly correct position in relation to the edge ofthe protective tube at the moment of introducing the device in theuterus. FIG. 2A shows an example of the correct positioning of theT-shaped device in the protective tube of the inserter. If the IUD ispulled into the protective tube by means of the removal string, which isthe case with the devices described above, it is understandable that itis difficult to make the IUD stop in the correct position if therelative movement of the protective tube and the plunger is notrestricted by any stop member. Pulling with too much force easily makesthe tips of the wings of the transverse member enter almost completelyinto the protective tube (FIG. 2B). During the insertion of the device,the sharp edges of the protective tube may interfere with theintroduction of the device through the cervical canal. If, on the otherhand, the device is not drawn deep enough into the protective tube, asituation occurs like that shown in FIG. 2C, in which the wings of thetransverse member project outwardly because of a too wide protectivetube. The diameter at the level of the wings remains too wide, whichmakes the introduction of the device during insertion more difficult. Itis easier to make the wings stop in the correct position (FIG. 2D) inthe case of the copper-wire devices, because the tube is narrow inrelation to the wings. Therefore there is no risk of the wings beingdrawn too deep into the tube even by forceful pulling.

Methods are known in the patent literature, according to which the IUDis placed within a protective tube when the device is being introducedinto the uterus. GP Patent 1,600,717 describes an inserter suitable forT-shaped or Y-shaped IUD's. The IUD is retracted into the protectivetube by means of an attached string. Patent publications U.S. Pat. No.3,842,826 and WO 94/13,233 also describe methods for retracting the IUDinto a protective tube before the insertion of the IUD. GB 1,403,393describes a method in which an IUD contained in a protective tube ispushed towards the end of the tube before the insertion of the device.

No method has been described earlier in which an IUD is introduced intothe protective tube by pushing the tube over the device, or by pullingthe device into the protective tube, where the relative movement of theplunger and protective tube is restricted by a stop member to ascertainthat the correct configuration of the IUD is achieved.

BRIEF SUMMARY OF THE INVENTION

It is the objective of the present invention to introduce a means toovercome the problems described above and to produce a new kind ofinserter which allows the correct positioning of an IUD also in thosecases in which the elongate member of a T-shaped IUD contains activematerial, which involves a diameter larger than that of the elongatemember of a copper-wire IUD. It is also our objective to produce aninserter which is firm and stable and where no risk of non-resilientbending of the protective tube is involved.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by referral to the followingdrawings, wherein

FIGS. 1A-1B illustrate as the technical level the unitary combination ofan inserter and an IUD

FIGS. 2A-2D illustrate T-shaped IUD's retracted into the protective tubein the correct or the wrong manner

FIGS. 3A-3D illustrate the operating principle of an inserter accordingto the invention

FIGS. 4A-4B illustrate the shape of the end of the plunger

FIG. 5 illustrates an embodiment of the invention

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1A shows a design according to the technical level, in which theT-shaped elongate member 45 of the IUD 40 has been placed in theprotective tube 12 of the inserter, and the wings 42 and 43 of thetransverse member of the IUD are expanded. The plunger 11 is a solid rodwith a handle 20 at one end. The withdrawal string(s) 41 run(s) in thespace between plunger 11 and protective tube 12. Reference No. 50 refersto a signalling device which can be slid along the surface of theprotective tube and placed in a desired location. When the IUD isinserted the signalling device is in contact with the cervical canal andsignals the correct depth of positioning the IUD. Before the device ismade operational the withdrawal string is pulled in the direction of thehandle 20. This allows the entrance of the IUD into the protective tube12, at which moment the wings 42 and 43 are folded against each other.FIG. 1B shows the IUD, protected by the tube 12, in the form in which itis inserted. After the assembly of FIG. 1B has been positioned in theuterus so that the IUD is correctly located the IUD is released byretracting the protective tube 12 outwardly while retaining the plunger11 stationary.

FIGS. 3A and 3B show an embodiment of the invention, which illustratesthe operating principle. FIG. 3A shows an inserter 10 with an IUD 40placed in the front end (entry into the uterus) so that the elongatemember 45 is inside the protective tube 12. Before insertion the string41 is tightened and locked in the locking device (15) associated withthe plunger 11, with the tip of the elongate member abutting the end ofthe plunger. The method described in this figure involves a hollowplunger, and the string 41 runs advantageously in the bore 13 of theplunger. The string thus slides freely, and there is no risk of itsgetting jammed between the plunger and the tube. The plunger has twoattached radial projecting stop members R2 and R4. The jacket of theprotective tube 12 has an axially directed slot 14 corresponding to thestop members R2 and R4 (the transverse cross-section is shown in FIG.3C) and designed to allow the movement of the protective tube 12 inaxial direction. The jacket of the protective tube has an attached stopmember R with stopping surfaces R1 and R3 projecting in the direction ofthe radius of the plunger. FIG. 3D is a cross-section showing stopmember R. Preparative to use of the device the tightening and locking ofthe withdrawal string is checked. Then, while holding the handle of theplunger, the protective tube is pushed towards the IUD until surface R1of stop member R abuts stop member R2, thereby stopping the movement ofthe protective tube. At this moment the IUD is substantially inside theprotective tube, and ready for insertion (FIG. 3B). The location of thestop members R1 and R2 has been designed such as to allow pushing theprotective tube past the plunger at a desired distance L, whichsubstantially corresponds to the length of the IUD assembled forinsertion. The stop members R1 and R2 are advantageously located so thatthe edge 12a of the protective tube that goes into the uterus is stoppedat a level at which the hemispherical tips 42a, 43a of the wings 42, 43of the transverse member of a T-shaped IUD partly remain uncovered bythe protective tube 12, while the wings 42, 43 still remain together.

Alternatively, the surface R1 of the stop member R can be kept incontact with stop member R2, wherein the protective tube extends pastthe plunger at a distance that essentially corresponds to the length ofthe IUD assembled for insertion into the uterus. If the IUD ispositioned in the device so that the elongate member 45 is positionedinside the protective tube but the wings 42, 43 are outside theprotective tube, the IUD can be positioned in the correct position forinserting by pulling the IUD into the protective tube.

The device according to FIG. 3B is pushed into the uterus until the IUDis in the correct location. The IUD is released from the protectivetube, while retaining the plunger absolutely stationary, by retractingthe protective tube towards the handle until the stop surface R3 abutsthe stop member R4 attached to the plunger. The location of the stopdevices R3 and R4 has been selected so that, when these stop devicesmeet, they indicate clearly the moment at which the IUD, at the forwardend of the plunger, has been released from the protective tube as itmoves towards the handle. The stop member R4 may but does not need to beconstructed such as to stop the movement of the protective tube in thedirection of the handle.

The stop members R2 and R4 need not, as shown in FIGS. 3A-3D, beattached to the plunger itself. Instead, they may form part of a memberwhich is itself connected to the plunger. The same applies to the stopmembers R1 and R3: They may be attached to the protective tube itself orto a member connected to the protective tube. The stop members R1 and R3may form part of the same member R, like in FIGS. 3A-3B, but they mayalso be separate members.

The plunger is advantageously hollow or has a groove running in theaxial direction and allowing the string 41 to slide freely in it.

It is important in the insertion of a T-shaped IUD that the wings can beprojected laterally and not forward or backward (as considered from thepatient). The directional stiffness of an IUD during insertion can beensured, for instance, by shaping the forward end of the plunger suchthat the IUD assumes a specified constant configuration when the stringis retracted. The IUD thus will not be twisted during insertion. Anexample of such a design is presented in FIGS. 4A and 4B. The end 45b ofthe elongate member abutting the plunger is shaped like an eyelet, whichhas an attached string 41 for retracting. The figures show that theforward end 11a of the plunger is not level but hollowed out to form asort of shallow funnel. When the string 41 attached to the eyelet 45b isretracted the eyelet 45b slides into the funnel and is caught there.FIG. 4A is a front view and FIG. 4B a side view of the eyelet 45.

The forward parts (directed towards the uterus) of the plunger and theprotective tube can be straight or curved so as to conform to theanatomy of the uterus.

A suitable embodiment of the invention is illustrated in FIG. 5. Theforward part 20' of the handle 20 forms a construction 21 running in thelongitudinal direction of the plunger. The construction has in theforward end 21' a channel in which the protective tube 12 will slide inthe longitudinal direction. The protective tube has a knob R at thedistal end (away from the uterus). The surface R1, in the direction ofthe uterus, of the knob R and the surface 21a, in the direction of thehandle 20, of the end 21' of the construction 21, together form a pairof stop members R1, R2. The edge R3, in the direction away from theuterus, of knob R and the surface 21b of the base of the construction 21together form a pair of stop members R3, R4.

If desired one or more signalling devices may be arranged between thestop members R1/R2 and R3/R4. Such a signalling device can, forinstance, be located in such a way that the doctor, when he prepares torelease the IUD, will notice the moment at which the wings of thetransverse member of the IUD have been released from the protective tubewhile the elongate member is still protected by the tube. Such asignalling device must not, of course, effectively stop the retractionof the tube, because then the IUD could not be released.

This invention provides for an inserter that allows the easy positioningof an IUD in a predetermined location in the protective tube, becausethe stop members guarantee an accurate positioning of the IUD duringinsertion and its accurate release. According to this invention it isnot necessary to provide so much clearing between the plunger and theprotective tube as in inserters in which the IUD's are positioned byretraction without any stop member which stops the movement of the IUD.This results in an extremely stable construction, which involves no riskof irremediable bending of the tube.

The inserter according to the invention is particularly suitable for thepositioning of T-shaped IUD's, but it is also applicable to other typesof IUD as long as these can be managed to enter the protective tube byappropriate arrangements.

While the invention is applicable to the positioning of IUD's of thecopper-wire type the advantages will be better appreciated in the caseof devices containing active agents. An inserter according to thisinvention is particularly suitable for the positioning of such aT-shaped IUD which has an elongate member 45 having a jacket-likepolymeric reservoir containing an active agent wound around it.

Suitable active agents include hormones used for the treatment ofmenopausal troubles or for contraception.

Those versed in the art will appreciate that many different variationsand adaptations of the present invention fall within the scope of theclaims presented in the following section.

We claim:
 1. An inserter for the positioning of an essentially T-shapedintrauterine device (IUD), said IUD comprising an elongated body havinga transverse member attached at one end of said body, said transversemember comprising two wings, which inserter comprisesa plunger having afront end adapted to receive the IUD and a rear end, a handle formedfrom or attached to the rear end of the plunger, a locking deviceoperatively attached to said plunger, said locking device adapted tolock a string attached to the IUD in such a way that the IUD remainsimmobile in relation to the front end of the plunger, and a protectivetube adapted to contain said IUD in a contracted configuration in whichsaid wings of the transverse member of an essentially T-shaped IUD arepressed against each other, said protective tube having a forward endadapted for insertion into the uterus and a rear end, wherein theprotective tube is fitted in slidable relationship around the plunger insuch a way that it can be pushed, at the forward end, past the plungerat a distance which corresponds substantially to the length of the IUDin said contracted configuration, and wherein the rear end of theprotective tube, has a first stop surface operatively attached thereto,and wherein the plunger, has a second stop surface operatively attachedthereto located in such a way that the said second stop surface willcontact said first stop surface and thereby stop movement of theprotective tube in the direction of the uterus when the forward end ofthe protective tube is in a position in which the tips of said wings ofthe transverse member of said T-shaped IUD remain partly uncovered bythe protective tube, but the wings nevertheless remain pressed againsteach other.
 2. The inserter according to claim 1, wherein the rear endof the protective tube, has a third stop surface operatively attachedthereto, andwherein the plunger has a fourth stop surface operativelyattached thereto, such that the said third and fourth stop surfaces,when they abut, indicate the moment at which the protective tube, whenmoving towards the handle, releases the IUD associated with the forwardend of the plunger.
 3. The inserter according to claim 2, wherein saidhandle includes a hollow front end which encompasses a portion of saidplunger and said protective tube, said handle having a longitudinal openchannel coaxial with said protective tube,wherein said first and thirdstop surfaces are located on opposite sides of a knob attached to orformed on said protective tube, with said knob positioned in saidchannel; and wherein said second and fourth stop surfaces comprise theopposite surfaces of the handle forming channel.
 4. The inserteraccording to claim 1, wherein the plunger has a hollow bore so that awithdrawal string of said IUD can run in the bore of the plunger.
 5. Theinserter according to claim 1 wherein the plunger has a concave frontend in which a tip of the elongated body of the IUD is caught when thestring is tightened, and twisting of the IUD during insertion is thusprevented.
 6. The inserter according to claim 1 wherein parts of theplunger and the protective tube that are adapted to be directed towardsthe uterus are curved.
 7. The inserter according to claim 1, incombination with an intrauterine device (IUD).
 8. The combinationaccording to claim 7, wherein an elongate member of the IUD comprises acore part around which a jacket-like polymeric reservoir containing anactive agent has been fitted.
 9. The combination according to claim 8,wherein the active agent is a hormone used for the treatment ofmenopausal troubles or for contraception.